DE102009056262A1 - Process for rolling a rolling stock - Google Patents

Abstract

The invention relates to a method for rolling a rolling stock (1) in a rolling stand (2) or in a plurality of rolling stands (2, 3), wherein on the rolling stand (2) spraying a cooling lubricant on the rolling stock (1) and / or on the Rolling (4, 5) of the roll stand (2) takes place. In order to increase the productivity of the rolling process and at the same time to save energy, the invention provides that in the case of using a rolling mill, the heat of the cooling lubricant heated by the rolling process is at a location downstream of the rolls (4, 5) in the rolling direction (W) taken up by a heat exchanger (14), to a location in the rolling direction (W) before the rollers (4, 5) passed (15) and there at least partially in the there on the rolling stock (1) and / or on the rollers (4 , 5) sprayed cooling lubricant is introduced by heat exchange.

Description

The invention relates to a method for rolling a rolling stock in a roll stand or in a plurality of rolling stands, wherein on the roll stand or on the rolling stands, a spraying of a cooling lubricant on the rolling stock and / or on the rolls of the roll stand.

A method of this kind is well described in the art. It has also become known to temper or prepare the cooling lubricant used in individual rolling stands in order to obtain favorable rolling conditions.

Examples of the various possibilities of providing or conditioning of cooling lubricant as well as generally the supply of cooling lubricant are in the JP 2007 237230 A , in the EP 1 829 623 A1 , in the JP 2000 094026 A , in the WO 98/51423 , in the EP 1 423 214 B1 , in the EP 1 829 625 A1 , in the DE 600 30 288 T2 , in the JP 5919 9109 A , in the JP 0815 5510 A , in the JP 2000 351002 A and in the JP 2007 253178 A described.

Accordingly, if necessary, several circles are provided for cooling lubricant for different rolling stands, wherein the flow temperature can be controlled. In rolling stands that are relatively far in the rolling direction at the end, it is possible to use cooling lubricant with a lower oil concentration in order to achieve improved strip cleanliness and better roughness transfer.

Working with a flow temperature that is constant across all scaffolds is a compromise. The resulting temperature control is not optimal.

Cold rolling plants usually also have one or at most two closed cooling lubricant systems in which the cooling lubricant is collected in the scaffold trays, pumped into a tank, filtered, conditioned and tempered and the spray bar for strip and tool cooling is fed back via a common feed. In this case, a medium (cooling lubricant) with the same state in the flow (regarding temperature, droplet size, soiling state, etc.) should provide both for the lubrication in the nip and for the cooling and cleaning of belt and rollers. The simultaneous fulfillment of these various tasks can thus only be a compromise for systemic reasons.

A negative effect of this compromise is that the temperature level at the first (possibly also at the second) engraving is usually too low, while the productivity of the plant is limited in the later stitches mostly due to high temperatures.

The present invention is based on the object to remedy this situation and to achieve improved lubrication in at least one rolling stand or part of the rolling stands, preferably in all rolling stands, in particular a lower resistance to deformation in the first (possibly also in the second) framework or stitch is to be achieved. In order to reduce the power and labor costs and so energy savings are achieved, the rollers should therefore be energy-saving possible. The productivity of the rolling process should thus be increased.

The solution of this object by the invention is characterized in that, with a view to rolling in a roll stand, the heat of the heated by the rolling cooling lubricant received at a location in the rolling direction behind the rollers by a heat exchanger, lying in a rolling direction in front of the rollers Directed site and there is at least partially introduced into the there on the rolling stock and / or on the rollers sprayed cooling lubricant by heat exchange.

The absorption of the heat of the cooling lubricant heated by the rolling process at the location downstream of the rollers in the rolling direction preferably takes place through a cooling element for the rolling stock and / or for the rolls. The temperature of the cooling lubricant used at the location lying in front of the rollers can be controlled or regulated by heat exchange to a predetermined value.

Furthermore, it can be provided that the volume flow of the heated coolant used is controlled or regulated to a predetermined value.

An analogous solution of the stated object is characterized in the case of using at least two rolling stands in that the heat of the heated by the rolling cooling lubricant received in or on the rolling mill in the following roll stand of a heat exchanger, passed to the upstream roll stand in the rolling direction and there at least partially introduced into the there on the rolling stock and / or on the rollers sprayed cooling lubricant by heat exchange.

The recording of the heat of the heated by the rolling cooling lubricant in or on the rolling mill in the following rolling mill takes place preferably by a cooling element for the rolling stock and / or for the rollers.

More preferably, more than two rolling stands are arranged successively in the rolling direction, wherein the heat of the heated by the rolling cooling lubricant received in or on a roll stand downstream in the rolling mill by heat exchange, passed to a rolling mill in the upstream rolling mill and there at least partially in the there on the Rolling and / or sprayed onto the rollers cooling lubricant is introduced by heat exchange.

The heat is absorbed by the heat exchanger is preferably carried out between two rolling stands following in the rolling direction.

The temperature of the coolant used in the roll stand upstream in the rolling direction can be controlled or regulated by heat exchange to a predetermined value.

Furthermore, the volume flow of the heated cooling lubricant used in the rolling mill upstream in the rolling direction can be controlled or regulated to a predetermined value.

The specification of desired temperatures and / or volume flows of the cooling lubricant in at least one rolling stand is preferably carried out by a process model. At least one measured rolling force in one of the rolling stands, at least one measured motor current of an electric drive of a roller, at least one measured motor torque of an electric drive of a roller or at least one temperature of the rolling stock measured at one point can be predefined for the process model.

The cooling lubricant heated by the rolling process may also be used from a rolling stand downstream in the rolling direction in a rolling mill upstream in the rolling direction to spray exclusively or additionally a selected area in the direction transverse to the rolling direction of the rolling stock and / or the rolls. In this case, it is particularly intended that the exclusive or additional spraying of the edge regions of the rolling stock and / or the rolls takes place (so-called hot edge spray).

The rolling process in question is preferably a cold rolling.

To achieve a good heat transfer can be provided that the cooling lubricant is sprayed onto the rolling stock at an angle to the rolling direction, preferably at an angle less than 45 ° to the horizontal.

The cooling lubricant used is preferably oil or emulsion.

The basic idea of the present invention is therefore to utilize the high waste heat which is produced in the rear stitches or stands due to the forming work, around the rolling stock, in particular the strip, and the rolls in the first pass (possibly also in the second pass) or frame to preheat. For this purpose, at least a part of the heat of the particularly highly heated cooling lubricant should be taken up and reintroduced into the front stitches or stands.

Thus, the invention proposes the use of the heated due to the naturally occurring process heat cooling lubricant for the targeted influencing of heat and volume flows.

The use of a process model for the pilot control of quantities, mixing ratios and temperatures substantially improves the proposed method. The regulation of the variables mentioned by process-model-based evaluation of measured process data (in particular rolling forces, motor currents, motor torques and strip temperature) further improves the process.

The use of the heat of the hot cooling lubricant as so-called "hot edge spray" or for other planarity influencing by thermal change of the roll contour offers an interesting extension of the functionality of the proposed method.

Accordingly, the productivity of the rolling process can be increased. Furthermore, more uniform process conditions can be achieved.

It also results in energy savings, especially in the first frame or the first stitch.

Overall, therefore, the following can be said concerning the advantages of the proposed method:
It results in improved lubrication and a lower resistance to deformation in the first (possibly also in the second) framework or stitch, resulting in a lower power and labor requirements and thus energy savings.

Furthermore, higher productivity is achieved, i. H. there is a higher decrease in the first pass, a higher rolling speed and / or a decrease in the further passes due to a more effective cooling device.

The volume flow is lower in the conventional media cycle.

Furthermore, there is a more uniform temperature distribution in the cooling lubricant, this results in a more uniform conditioning of the coolant, z. B. a lower risk of bacterial growth in emulsions.

The temperature of the applied medium in the first (possibly also in the second) framework or engraving can be adjusted in a targeted manner by utilizing the heat of the hotter cooling lubricant, ie. H. controlled or regulated. This can advantageously be predetermined or regulated by means of a suitable process model, wherein the process model makes use of measured process parameters and the plant state (eg warm-up phase).

In the drawing, an embodiment of the invention is shown. Show it:

1 schematically a cold rolling mill in the side view, in which a rolling stock is rolled in the form of a strip, and

2 a chilled beam that applies cooling lubricant to the surface of the rolling stock via nozzles.

In 1 is a rolling mill to see a number of rolling stands 2 . 3 . 6 and 7 having. In the rolling mill is a rolling stock 1 , in this case a strip, rolled. Every rolling stand 2 . 3 . 6 . 7 has (at least) two cooperating rolls 4 . 5 , The first rolling stand in the rolling direction W 2 performs the first stitch. The last rolling stand in the rolling direction W is the rolling stand 3 ; in between are more rolling stands 6 . 7 arranged.

About leads 10 becomes chilled beam 8th covering the top and bottom of the band 1 spray with cooling lubricant, which supplies cooling lubricant. The sprayed-on cooling lubricant can in a lower portion of the rolling mill of collecting trays 11 be caught, with a drip tray 11 only for the rolling stand 3 outlined.

It is essential that the heat of the cooling lubricant heated by the rolling process in a roll stand following in the rolling direction W - in the present case behind the roll stand 7 - from a heat exchanger 14 is recorded in the form of a belt cooling. This heat is transmitted via a heat pipe 15 to the upstream in the rolling direction W first mill stand 2 directed, as indicated schematically. There, the heat by means of another heat exchanger 16 (Which is only indicated very schematically) introduced into the cooling lubricant, here from a supply line 10 is supplied from. The cooling lubricant is so by the between the rolling stands 7 and 3 warmed up by heat absorbed by strip cooling, which is done by the described heat exchange.

The technology of the heat exchangers is well known as such, so that it need not be discussed in detail.

Cooling of the belt 1 done by chilled beams 8th that with nozzles 9 are provided as it is 2 evident. The chilled beam 8th has nozzles in the embodiment 9 whose spray direction is directed against the rolling direction W and the angle, moreover, includes an angle α, which in the exemplary embodiment is approximately 30 °. This countercurrent cooling uses the resulting turbulence for efficient heat exchange.

A reduction of the rolling torque by a suitable preheating we achieved by lowering the Umformfestigkeit the band and / or by reducing the nip friction. With emulsions, higher temperatures also result in improved deposition of the oil phase and thus more stable lubrication conditions.

The preheating requires in the first stitch or scaffold a significantly higher flow temperature. Although this could be achieved by a heater, it is energetically more advantageous to use the waste heat from the rear stitches or scaffolding.

In order to bring the cooling lubricant there to a high temperature, efficient cooling devices, which manage with relatively low volume flows, are particularly suitable.

In 1 Incidentally, another additive possibility is outlined, with which an efficient further temperature control of the cooling lubricant on upstream rolling stands - in particular on the first rolling stand 2 - can be done. After that it can be provided that in a downstream roll stand (eg on the rolling stands 6 . 7 and 3 ) is collected by the rolling heated cooling lubricant, including the already mentioned drip trays 11 can be provided. The heated coolant is then transferred via a pipe 12 with pump 13 to an upstream rolling stand - in the exemplary embodiment of the roll stand 2 - conveyed and here, possibly mixed with fresh coolant, to the rolling stock 1 or on the rollers 4 . 5 sprayed.

The according to 2 sketched application of the cooling lubricant is carried out according to the countercurrent principle with turbulence generation, which ensures a good heat transfer.

That from the downstream rolling stands 6 . 7 . 3 The strongly heated medium originating from it can thus - at least in large part - be caught and in the first stitch or framework 2 be re-applied on the inlet side. If at all, filtration must be carried out only roughly, since the demands on the cleanliness of the cooling lubricant are lowest in the first stand or stand. The cooling lubricant then returns to the conventional medium cycle via the scaffolding trough.

The heat exchange according to the invention for absorbing heat from the heated cooling lubricant can, of course, take place between or on each of the downstream sketched and possibly also between or on further rolling stands.

It is also possible to use the principle according to the invention on a single roll stand. After that, in the rolling direction behind the rollers 4 . 5 Heat exchange carried out, the heat against the rolling direction W conveyed forward and preheated here, the cooling lubricant with this heat.

The maximum forming capacity or productivity can thus be increased. Optimum lubrication conditions can be set specifically.

LIST OF REFERENCE NUMBERS

1

rolling

2

rolling mill

3

rolling mill

4

roller

5

roller

6

rolling mill

7

rolling mill

8th

Chilled beams

9

jet

10

supply

11

drip tray

12

management

13

pump

14

Heat exchanger (cooling element)

15

heat conduction

16

heat exchangers

W

Rolling direction angle

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2007237230 A [0003]
• EP 1829623 A1 [0003]
• JP 2000094026 A [0003]
• WO 98/51423 [0003]
• EP 1423214 B1 [0003]
• EP 1829625 A1 [0003]
• DE 60030288 T2 [0003]
• JP 59199109 A [0003]
• JP 08155510 A [0003]
• JP 2000351002 A [0003]
• JP 2007253178 A [0003]

Claims (20)

Method for rolling a rolled product ( 1 ) in a rolling stand ( 2 ), wherein on the roll stand ( 2 ) a spraying of a cooling lubricant on the rolling stock ( 1 ) and / or on the rollers ( 4 . 5 ) of the roll stand ( 2 ), characterized in that the heat of the heated by the rolling cooling lubricant at a in the rolling direction (W) behind the rollers ( 4 . 5 ) lying by a heat exchanger ( 14 ), in a rolling direction (W) in front of the rollers ( 4 . 5 ) ( 15 ) and there at least partially in the there on the rolling stock ( 1 ) and / or on the rollers ( 4 . 5 ) sprayed coolant is introduced by heat exchange. A method according to claim 1, characterized in that the recording of the heat of the heated by the rolling cooling lubricant on the in the rolling direction (W) behind the rollers ( 4 . 5 ) by a cooling element for the rolling stock ( 1 ) and / or for the rollers ( 4 . 5 ) he follows. A method according to claim 2, characterized in that the temperature of the at the front of the rollers ( 4 . 5 ) lying location coolant is controlled or regulated by heat exchange to a predetermined value. A method according to claim 2 or 3, characterized in that the volume flow of the heated coolant used is controlled or regulated to a predetermined value. Method for rolling a rolled product ( 1 ) in at least two in the rolling direction (W) successive rolling stands ( 2 . 3 ), wherein at least two rolling stands ( 2 . 3 ) a spraying of a cooling lubricant on the rolling stock ( 1 ) and / or on the rollers ( 4 . 5 ) of the rolling stands ( 2 . 3 ), characterized in that the heat of the cooling lubricant heated by the rolling process in or on the roll stand (B) following in the rolling direction (W) ( 3 ) from a heat exchanger ( 14 ), in the rolling direction (W) upstream rolling stand ( 2 ) ( 15 ) and there at least partially in the there on the rolling stock ( 1 ) and / or on the rollers ( 4 . 5 ) sprayed coolant is introduced by heat exchange. A method according to claim 5, characterized in that the absorption of the heat of the heated by the rolling cooling lubricant in or on the rolling mill in the following direction (W) rolling stand ( 3 ) by a cooling element for the rolling stock ( 1 ) and / or for the rollers ( 4 . 5 ) he follows. Method according to claim 5 or 6, characterized in that more than two rolling mills ( 2 . 3 . 6 . 7 ) are arranged successively in the rolling direction (W), wherein the heat of the cooling lubricant heated by the rolling process in or on a rolling stand (B) following in the rolling direction (W) ( 3 ) received by heat exchange, to a roll in the direction (W) upstream rolling stand ( 2 . 6 . 7 ) and there at least partially in the there on the rolling stock ( 1 ) and / or on the rollers ( 4 . 5 ) sprayed coolant is introduced by heat exchange. A method according to claim 7, characterized in that the absorption of heat by the heat exchanger ( 14 ) between two in the rolling direction (W) subsequent rolling stands ( 3 . 6 . 7 ) he follows. Method according to one of claims 5 to 8, characterized in that the temperature of the in the rolling direction (W) upstream rolling stand ( 2 ) is controlled or regulated by heat exchange to a predetermined value. Method according to one of claims 5 to 8, characterized in that the volume flow of the in the rolling direction (W) upstream rolling stand ( 2 ) controlled heated coolant to a predetermined value or regulated. Method according to one of claims 1 to 10, characterized in that the specification of target temperatures and / or volume flows of the cooling lubricant in at least one rolling stand ( 2 . 3 . 6 . 7 ) takes place through a process model. A method according to claim 11, characterized in that the process model at least one measured rolling force in the roll stand ( 2 ) or in one of the rolling stands ( 2 . 3 . 6 . 7 ) is given. A method according to claim 11, characterized in that the process model at least one measured motor current of an electric drive of a roller ( 4 . 5 ) is given. A method according to claim 11, characterized in that the process model at least one measured motor torque of an electric drive of a roller ( 4 . 5 ) is given. A method according to claim 11, characterized in that the process model at least one temperature of the rolling stock ( 1 ) is given. Method according to one of claims 1 to 15, characterized in that the heated by the rolling cooling lubricant from one behind the rollers ( 4 . 5 ) or one in the rolling direction (W) following rolling stand ( 3 ) in front of the rollers ( 4 . 5 ) or in a roll stand (W) upstream rolling stand ( 2 ) is used to exclusively or additionally a selected area in the direction transverse to the rolling direction (W) of the rolling stock ( 1 ) and / or the rollers ( 4 . 5 ) to spray. A method according to claim 16, characterized in that the exclusive or additional spraying of the edge regions of the rolling stock ( 1 ) and / or the rollers ( 4 . 5 ) he follows. Method according to one of claims 1 to 17, characterized in that the rolling of the rolling stock ( 1 ) is a cold rolling. Method according to one of claims 1 to 18, characterized in that the cooling lubricant to the rolling stock ( 1 ) at an angle (α) against the rolling direction (W) is sprayed, preferably at an angle (α) between 20 ° and 45 ° to the horizontal. Method according to one of claims 1 to 19, characterized in that oil or emulsion is used as a cooling lubricant.

Images